BIOL 303 Lecture Notes - Lecture 17: Lateral Plate Mesoderm, Pitx2, Sex-Determination System
27 Apr 2016
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Recall two organizers in mouse ; 1)ave : req for head spec 2)node: req for trunk and tail spec. S46 lr axis spec in mammals: ex liver on right side, heart on left, paired organs such as lung : there are differences btwn the right lung (3lobes) vs left lung (2 lobes) S47 node is imp in lr spec (mutations where node doesn"t form: lr axis doesn"t from properly). At end of primitive streak , we have the node (locate). Looking closer at node, have two cell types in node: 1)pit cells 2)crown cells (surrounding pit cells) = both are imp in lr spec. zoom into pit cells: each pit cell has a single motile cilia (mono-ciliated). S48 cilia is always at 45 degree angle relative to pit cell. All cilia are angled in the same direction and they all turn in the same direction, causing a flow of fluid from right left : node cilia causes a leftward flow.
